When the kpkeys_hardened_pgtables feature is enabled, we need to be
able to modify attributes (specifically the pkey/POIndex) in the
linear map at page granularity.

Add the appropriate check to can_set_direct_map() on the same
principle as rodata_full and other features.

kpkeys_hardened_pgtables currently requires the linear map to be
fully PTE-mapped, so we also need to ensure that force_pte_mapping()
returns true, like for DEBUG_PAGEALLOC.

Both functions can be called very early, before POE is actually
detected, so the early_enabled() helper is used.

Signed-off-by: Kevin Brodsky <[email protected]>
---
 arch/arm64/mm/mmu.c      | 2 +-
 arch/arm64/mm/pageattr.c | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 493310cf0486..f79e82c0674a 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -760,7 +760,7 @@ static inline bool force_pte_mapping(void)
        const bool bbml2 = system_capabilities_finalized() ?
                system_supports_bbml2_noabort() : cpu_supports_bbml2_noabort();
 
-       if (debug_pagealloc_enabled())
+       if (debug_pagealloc_enabled() || 
kpkeys_hardened_pgtables_early_enabled())
                return true;
        if (bbml2)
                return false;
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index ecdfaa9701e1..4405f93f1586 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -101,7 +101,8 @@ bool can_set_direct_map(void)
         * Realms need to make pages shared/protected at page granularity.
         */
        return rodata_full || debug_pagealloc_enabled() ||
-               arm64_kfence_can_set_direct_map() || is_realm_world();
+               arm64_kfence_can_set_direct_map() || is_realm_world() ||
+               kpkeys_hardened_pgtables_early_enabled();
 }
 
 static int update_range_prot(unsigned long start, unsigned long size,

-- 
2.51.2


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